(1) Field of the Invention
The present invention relates generally to testing of flexible tubes, and more particularly to a system for testing a flexible tube, e.g., biomedical tubes, that minimizes unwanted stress on the tube while simulating an actual use environment.
(2) Description of the Prior Art
In many applications involving the use of flexible tubing, it is desirable to determine the tube's mechanical properties and to know how the tubing will react under load conditions. Accordingly, sample lengths of the purposed tubing must be tested in either actual use or in a test environment. In cases where tube performance is critical (e.g., shock testing, environmental and hazardous material testing, biomedical tube applications to include artificial arteries and other biofluid ducts), testing in an actual use environment is not an option. Thus, many types of flexible tubing must rely on lab testing.
Currently, it is difficult to grip materials such as thin-walled tubing in a manner that does not distort the cylindrical shape. Conventional lab testing techniques generally pinch the ends of the tube such that the resulting shape is no longer cylindrical. The shape distortion causes stress concentrations to develop in the gripping area that can lead to premature failure. However, the shape change in the gripping area can also negatively affect areas along the test section of the tube. In addition, there are no practical test means of holding flexible tubes while applying an internal pressure to them for the purposes of testing the tube's fluid transport performance while under a loaded condition.